1. Field of the Invention
The present invention relates generally to auto-focusing camera modules and auto-focusing lens modules, more particularly, to a small sized digital camera module used in a portable electronic device such as a mobile phone or a Personal Digital Assistant (PDA).
2. Description of Related Art
Recently, with the development of wireless communication technologies, digital cameras have become widely used in mobile phones, PDAs, and other electronic devices.
Generally, digital cameras typically use an image pickup device, such as a Charge Coupled Device (CCD) or Complementary Metal Oxide Semiconductor (CMOS) for capturing images. In the digital camera, an object image formed on the image pickup device through a lens is converted into an electrical signal by the image pickup device, and the electrical signal is stored as a digital signal in a mobile phone or PDA in which the digital camera is mounted.
Since the digital camera is desirably to be mounted in mobile phones or PDAs, a fixed focus lens module is usually used to facilitate mounting thereof within a small phone or PDA. However, images photographed by a digital camera with a fixed focus lens module tend to be poor in quality. It is partly due to the fixed focus lens, which is incapable of adjusting focal length to make a clearer image.
What is needed, therefore, is an auto-focusing camera module which is suitable to be used in mobile phones or PDAs.